The present invention relates to paper handling. Select embodiments of the invention are particularly well-suited for use in the waste paper recycling industry.
Environmental campaigns and recycling in many offices have generated a supply of recyclable waste paper. However, waste paper sorting is still currently performed almost entirely by manual sorting. This is time consuming and expensive. Thus, heretofore it has generally been more economical to use raw paper material than sort and process recyclable waste paper.
Numerous automated waste separation techniques are known. However these systems are designed for recovery of non-ferrous metals, aerospace alloys, municipal waste, mixed recyclables and plastic containers. Paper sorting presents unique problems not overcome by prior art separation techniques.
The unique problems encountered when attempting to sort waste paper is due to the relatively light weight and flexible nature of pieces of paper. These characteristics make it difficult to supply paper to a sorting sensor. Even when waste paper has been supplied to a sensor, it has not been supplied at a sufficient feed rate, e. g. pieces per hour (PPH), to be cost effective. Prior art sensors operate on the basis of an eddy current created by the waste stream as it passes through the sensor, diffusion of light transmission through the waste e. g. transparent glass, and the like. These techniques are inapplicable to sorting waste paper because the paper has no metallic components and the paper is opaque to light. Thus, not only must an effective paper sorting sensor be designed, an effective paper handling system must be designed to supply waste paper in sufficient feed rates to the effective paper sorting sensor. Prior art paper handling techniques have been unsatisfactory in overcoming these obstacles.
The present invention relates to paper handling and sorting methods and devices.
A paper handling system includes an acceleration conveyor including an acceleration belt operating at an acceleration speed. A pinning structure is operably positioned to pin paper to the acceleration belt. The pinning structure may be a rotary feeder positioned above the acceleration belt. The rotary feeder includes a plurality of flexible bristles extending radially from a roller and contacting the surface of the acceleration belt. The speed of the acceleration belt is sufficiently high to create a suction phenomena such that when a sheet of paper is pinned in close contact to the acceleration belt, it will be accelerated to a paper speed substantially equal to the acceleration speed.
In another embodiment, the paper handling system includes an acceleration conveyor adapted to feed paper to a device at a predetermined speed. A product conveyor is located downstream of the acceleration conveyor. A transition gap is located between the acceleration conveyor and the product conveyor. A blowing system is operatively positioned to facilitate carrying the paper across the transition gap at a speed substantially equal to the speed at which the paper is moving on the acceleration conveyor.
Accordingly an object of the present invention is to provide means and methods for achieving a cost effective recycled machine grade paper fraction from a paper waste stream.
Another object of the present invention is to provide means for achieving automated sortation on a cost effective basis.
Another object of the present invention is to provide means for achieving improved consistency and repeatability in the quality of recycled waste paper.
Another object is to reduce labor requirements for sorting waste paper.
Another object of the present invention is to provide means and methods to accelerate and spread paper to operably thin layers to achieve an effective sort.
A further object of the present invention is to perform the sort at high speeds.
An object of the present invention is to incorporate automated sortation into a paper handling system to achieve consistent grades of premium paper from waste paper.
Other and further objects, features and advantages of the invention will be readily apparent to those skilled in the art upon a review of the following disclosure when taken in conjunction with the accompanying drawings.